When GpgOL uses the internal keycache the keys might have changed externally between caching and the actual crypto action.

So in case the crypto action fails with "unusable key" errors it would be nice if the keys would be flushed from the cache and the external resolution (which always uses up to date information) is used.

I give this low priority as I don't see a regular use case for deleting or otherwise messing (e.g. revoking) keys in the day to day use.